Infections are a major source of healthcare expenditure. Approximately 5% of all surgical wounds become infected with microorganisms, and that figure is considerably higher (10-20%) for patients undergoing abdominal surgery. Bacterial species, such as Escherichia coli (E. coli) are the most frequently isolated organisms from infected wounds. Bacterial colonization rates are significantly higher in the hospital setting, both among healthcare workers, and among patients. Moreover, the colonizing organisms in the hospital environment are likely, to be resistant to many forms of antimicrobial therapy, due to the strong selective pressure that exists in the nosocomial environment, where antibiotics are frequently used. Most strains of Escherichia call can harmlessly coexist with humans, for example, in their intestines, and are not likely to cause disease under normal circumstances. Some strains, however, produce toxins that can cause severe, even life threatening disorders, including intestinal disorders, kidney disorders, and urinary tract infections.
Escherichia coli are one type of pathogenic microorganism that can be found infections in the human body; others include, but are not limited to Streptococcus pyogenes, Pseudomonas aeruginosa, Enterococcus faecalis, Proteus Serratia marcescens, Enterobacter clocae, Acetinobacter anitratus, Klebsiella pneumoniae, and Staphylococcus species.
Infection, including wound infection due to any of the above organisms is a significant concern of hospitals. The most common way of preventing such infection is to administer prophylactic antibiotic drugs. While generally effective, this strategy has the unintended effect of breeding resistant strains of bacteria. The routine use of prophylactic antibiotics should be discouraged for the very reason that it encourages the growth of resistant strains.
Rather than using routine prophylaxis, a better approach is to practice good anti-microbial management, i.e., keep area at risk for becoming infected away from bacteria before, during, and after surgery, and carefully monitor the wound site or patient fluid for infection. Normal monitoring methods include close observation of the wound site for slow healing, signs of inflammation and pus, as well as measuring the patient's temperature for signs of fever and testing the patient's fluids, for example, urine, for signs of infection. Unfortunately, many symptoms are only evident after the infection is already established. Furthermore, after a patient is discharged from the hospital they become responsible for monitoring their own healthcare, and the symptoms of infection may not be evident to the unskilled patient.
A system or biosensor that can detect the early stages of infection before symptoms develop would be advantageous to both patients and healthcare workers. If a patient can accurately monitor the condition of a wound after discharge, then appropriate antimicrobial therapy can be initiated early enough to prevent a more serious infection.